Zinc-furnace.



PATEN TED DEG. 5, 1905.

ZINC FURNACE. APPLICATION FILED 22.12, 1905.

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PATENT, OFFICE."

EMILE DOR-DELATTRE, OF BUDEL, NETHERLANDS.

zlNc-FuRN oE.

, Specificatioh of Letters Patent.

PatentedDec. 1905.

. Application filed April 12, 1905. Serial No. 255.247.

: To all whom itmay concern:

Y Be it known that I, EMILE DOR-DELA'ITRE, a subject of the King of Belgium, residing at Budel, Netherlands, have invented certain new and useful Improvements in-Zinc-Furnaces;

and I do hereby declare the following to be a full, clear, and exact description of the inventlon, such as will enable others skilled in the art to which it appertains to make and-use the same.

The retorts of zinc-furnaces are very easily and very rapidly attacked by the gangue of the ores when the temperature in the furnace attains a certain degree,- which is practically that necessary to obtain a good reduction of the oxids of zinc. It follows that the'heating of such furnaces is a matter of particular delicacy, as the smallest change of temperature in any "part of the furnace due to even the" slightest irregularity in the uniformity of the heating would cause the destruction of a number,if not the whole, of the retorts. This is especially to be feared in a regenerative gasfurnace, which necessarily is, of all lnetallun gical furnaces, that which lacks most of the conditions required for obtaining a constantand regular temperature in every part.v These furnaces'are always of large capacity, and the .gas is compelled to make a considerable travel, during which the combustion should be as active at the end as at the commencement, while the multiplicity of retorts is an obstacle to ,the complete and regular combustion of the gas. Further, in order to heat the large retort-chambers a considerable quantity of gas v must be used; but the necessary reactions can be produced by a comparatively small number of calories and at 'arela'tivelylow temf' perature, (about1,500 It is thus necessary to very'regularlyheat a large space with little gas, to obtain a regular combustion of gas during its extended passage through chambers impeded by numerous retorts, and, in

fact, to obtain and maintain a temperature which reaches the extreme limit of that which the retorts can endure. In, present practice the attainment of this result depends upon the economy of combustion by sending into the furnaces a considerable quantity of gas and by using only apart of it, the excess being ejected through the chimneys, above which it I generallyburns and gives a large flame; but even by employing this excess quantity of 1 gasv it frequently vhappens, however much care is given to the construction of the furnace, that during the working an irregular heating;

annexe-d. drawingsthese openings are very, if not absolutely, in-

accessible. They cannot-be cleaned while the furnace is in operation,- andonels compelled to stop the operation of the furnace inorder to remove the obstructions. 1 In;order to avoid these stoppages as much as;possible, these openings are made ofa sufiiciently large secj z 'tion' to economize the gas, and ;it 1S-' 1I1 order to obtain under these conditionsjaj good dis; tribution of gas in thefurnacethatit becomes necessary to employ a considerable excess;

In the furnace which is the object of; the pres- Y ent invention these various inconveniences are avolded 1n consequenceofgthe shape and the position given to the openings for theair and-the gas, as well as the"pos'sibility of{,al-

tering the shape and section even during the operation of the kiln, likewise the shape and position of the-openings which connect the two'retort-chambers of the furnace. These arrangements'are obtained by making the furnace of large capacity and in such a manner as to always insure an absolutely regular heat; ing action in all parts without necessitating the supply of gas in excess to the chambers; The improved furnace is represented in the Figure 1' is a verticaland transverse section on A B, Figs. 2 and 3. Fig. 2 is a lon gitudinal vertical section on C D. Fig. 3 is a-horizontal-section on -E F.

,The furnace, which is .of the ,Siemens re,-

versing type, .is formed of twochambers a and a in communication with each other by the openings; 0.; They are 'closedby the archesc and 'v, in "'hich are made at distances apart the longand narrow burner-gaps f and f,

affording passages for the air and gas coming from the regene'rators and for the productsof combustion proceeding to theregenerators; The passages on m andmt n extend through the whole length of the furnace, the passages m and m being in communication with the airregenerators situatedxat one end of the fur,- nace, whilethe channels 70 and 11. communicate with the gas-recuperators placed at the sideof the former, while the whole of the passages are in communication with the chambers a and a by the gaps f and f b b and b 5', Figs. 1 and 3, are movable blocks or slabs placed on the gaps f and f.

oand are openings made in the walls 0 and c, permitting of an easy access to the gaps f and f and to the blocks 7) band I) They are closed by movable refractory plugs.

tand t are passages through the walls d and d, wherethrough the blocks 6 I) and I) b may be passed.

The results obtained by this arrangement are as follows:

First. Such an arrangement of openings for the entrance of air and gas to the upper part of I the kiln permits (a) of their easy accessibility.

The mere inspection of the figures at once shows how easy it is to reach, through the openings 0 and 0, the gaps f and f and to maintain them in a perfect order. (6) The reduc tion of the number of these openings. As can be seen by an inspection of Figs. 2 and 3, the number of gaps f and f along the length of the furnace is very much reduced. For a furnace of the type given a single gap is sufficient, for example, for six vertical rows of retorts. This result is obtained by placing each gap over the axis of a retort.

vertically are divided to the right and to the left of the retortand spreading horizontally are sufficient to heat six vertical rows of retorts.

Second. The shape of the openings for the entrance of the air and gas permit of obtainvery long and very narrow, (length about twenty times the breadth,) so that the gas and air at the moment of entering the furnacechambers form two very thin vertical currents having contact with an extremely-reduced surface.

Third. The possibility of altering or adjusting the shapes or sizes of the openings for the air and gas, which enables the combustion of the gas to be accelerated or retarded as required. Fig. 1 shows how the shape and size of the gaps f and f can be altered by means of the movable blocks 6 b b b. By placing the blocks as indicated at the left side of Fig. 1 the currents of air and gas are compelled to approach and intermix with one another, and the mixing commences to take place in the same gap which assists or insures the combustion of the gas to its entrance to the furnace. If, on the contrary, the blocks are placed as indicated in the right-hand side of Fig. 1, they separate the air from the gas and retard the combustion, and this action can be regulated to any desired extent by increasing more or less the number of blocks which separate the air from the gas.

Fourth. The possibility of altering the sec- (See Fig. 2.) The currents of air and gas striking it tion of the openings giving passage to the air and the gas, which permits of regulating very precisely the heat throughout the length of the furnace. If, for example, in the two cases indicated in Fig. 1 it is desired to increase or decrease the passage for the air and the gas or either of the said passages, all that is necessary is to increase or diminish the number of blocks placed upon the gapsff in the two series of channels m m and n a or upon one of these two series only.

With regard to the position and shape of the openings which connect the two chambers of the furnace these openings serve not only to connect the two chambers a, and a, but also to compel the proper mixing of the air and the part of the gas which has not been burned in the chamber a before their entrance in the chamber a, and also to insure complete combustion of the whole of the gas. Without this intimate mixing, obtained at this moment, the combustion in the chamber a would not be complete, by reason of the fact that the quantity of air and gas which remains disposable for this part of the furnace occupies (by reason of the shape of the gaps f) the exterior edges of two currents which the said gas and air form on their entrance into the chamber, and also by reason of the fact that the said unconsumed gas and air are already separated by a considerable quantity of burned gas, which renders this mixing and the complete combustion more difiicult. The passages p, by reason of their shape and position, compel the effective mixing of the unconsumed air and gas before they pass into the second chamber. Their total section and length is approximately equal to that of the gaps f and f, but they differ in their height, (length in the gaps f and f which is considerably reduced, and their number is much greater (one for each vertical row of retorts) and they are distributed or arranged along the whole length of the furnace. The effect of these chambers is to divide and split up the gases from the chamber a at the moment of their entrance into the chamber a and also to insure a good mixture of the unburned air and gas, and consequently a complete combustion of the latter in the second chamber.

The gas employed in these furnaces can be obtained from any solid fuel; but preferably gasified liquid fuel is employed.

Having fully described my invention, what I desire to claim and secure by Letters Patent is 1. A zinc-furnace having air and gas channels m, a, m, a communicating with the chambers 00, a by burners f, f consisting of long and narrow gaps or openings, which also serve as passages for the air and gas, these burners being provided with movable blocks, slabs or equivalent means whereby the currents of gas or gas and air can be altered at the moment of entering the furnace,

thus providing for the easy regulating ofthe furnace and insuring completecombustion.

2. In a gas-heated zinc-furnace, the combi-- nation with a furnace-chamber, of air and gas channels adapted to communicate with the chamber through a common passage, adjustable means for regulating the admission of air and gas to said common passage, and meanswithin the chamber in alinement with said passage to deflect laterally the currents entering the chamber through said passage.

3. In a gas-heated zinc-furnace, the combination witha furnace-chamber adapted to support a series of retorts, of air and gas channels arranged to communicate with-said chamber through a commonvpassage, said passage being in alinement with a retort in the chamber, whereby the gaseous currents will be defiected in opposite directions on entering said chamber.

4. A gas-heated zinc-furnace having independent air andgas channels, and a chamber adapted to support a series of retorts, the roof of the chamberhaving formed therein a plurality of narrow apertures each communisaid apertures being each arranged in line I with a retort in said chamber, and a plurality of retorts being arranged in each of the spaces between said apertures;

5. A gas-heated zinc-furnacehaving two furnace-chambers each adapted to support a series of retorts, independent air and gas channels communicating with each of said furnace-chambers through apertures each communicating with both said air and gaschannels arranged in line with a retort in the chamber; a plurality of retorts being arranged in each of thespaces between'said apertures, and a series of passages extending through the wall separating the furnace-chambers and corresponding in number to the vertical rowsof retorts. e

In testimony whereof I have signed my name to this specification in the presence of two sub scribing witnesses. EMILE DOR-DELATTREJ Witnesses:

ARMANI) PIGARD, PAUL SEPULOHRE. 

